1. Field
The present invention relates to a battery module receiving apparatus and a power storage system comprising the same, and more particularly, to a battery module receiving apparatus for easily receiving and replacing battery cells or modules and a battery module thermostat and for uniformly controlling the temperature between the battery cells, a battery module thermostat, and a power storage system comprising the same.
2. Description of Related Art
A secondary battery has high applicability depending on the product group and excellent electrical characteristics such as high energy density, and thus is commonly used as an electric power source of electric vehicles (EVs) or hybrid vehicles (HVs) as well as mobile devices.
This secondary battery is repeatedly charged and discharged by electrochemical reactions between the components or elements including an electrode current collector, a separator, an active material, an electrolyte, and an aluminum thin-film layer, and thus has a primary advantage of greatly reducing the use of fossil fuels. Also, since a secondary battery does not generate by-products that come with energy consumption, it can improve energy efficiency and is considered environmentally friendly. For these reasons, a secondary battery is gaining attention as an alternative energy source.
A secondary battery as an elementary unit is a battery cell, a plurality of secondary batteries are an assembly or a battery module, and a plurality of assemblies are a battery pack. However, the present invention is not limited in this regard. Unless otherwise stated, a secondary battery stated herein is used to commonly indicate a battery cell, a battery module, and a battery pack.
Recently, with the increasing significance of global issues relating to the exhaustion of energy resources such as fossil fuels, environmental pollution, economically efficient energy use, and the like, a smart grid system has been actively studied to effectively overcome the inequality in power consumption and power production and solve the problems caused thereby, such as, for example, the waste of power when power is oversupplied and power overload when power supply is in shortage. The smart grid system flexibly controls the power supply using a variety of information and communication infrastructures.
In other words, the infrastructure of a smart grid system is configured to store surplus power when power consumption is low and supply the stored power with supply power to consumers when power consumption is high.
In this instance, the smart grid system needs a medium for storing power. As such a medium, a secondary battery or a battery pack is dominantly used.
A power storage system may be used in various fields as well as smart grid systems. For example, a power storage system may be used in EV charging stations that store a great amount of power needed to supply to EVs.
To implement a high capacity power storage system, a battery pack constituting the system includes a considerable number of secondary batteries assembled in various configurations, for example, a tower-type stack battery pack in which battery packs are vertically stacked. However, since a secondary battery is repeatedly charged and discharged by electrochemical reactions inside the battery, the secondary battery cannot avoid the heat generated during charging and discharging. The heat generation dramatically increases during charging and discharging as the capacity is higher.
Heat may cause potential injury or damage to a secondary battery allowing electrochemical reactions, resulting in deterioration in the performance of the battery, which may not guarantee the life of the battery. Furthermore, heat is also known as a fatal factor exerting a bad influence on the safety of the battery, which may cause explosion and the like.
Accordingly, a secondary battery needs cooling during operation. Particularly, in the case of a high-capacity high-integration power storage system, a cooling system is even more necessary to solve the heat generation problem.
However, a conventional cooling system only focuses on cooling an individual battery cell or module rather than the entire power storage system.
Since the conventional cooling system employs an independent operation to individually cool battery cells or modules constituting a tower-type stack battery pack, there is variation in the cooling performance, which makes it difficult to uniformly cool the battery cells or modules. Also, excessive cooling may occur due to overlapping in cooling. To enable individual control, a battery management system (BMS) suitable for individual control and logic for operating such a BMS should be provided, and as a result, a complex air conditioning system along with very low efficiency in the maintenance and repair of the system are posed.
On the other hand, when the temperature of a secondary battery becomes too low at cold start, the performance of a power storage system may reduce. In this case, suitable heating is required. Accordingly, there is a need for a mechanism for properly maintaining the temperature of a secondary battery through suitable cooling and heating and for easily and uniformly controlling the temperature between battery cells, between battery modules, or further between battery packs.